Underreaming-bit.



H. J. FREEON.

UNDERREAMING `BI'I'.` APPLICATION FILED MAY 31. IQIe.

Patented Mar. 27, 1917.

@n0/.Uffa @0m HENRY J. rennen, or sanita refiera; oanironivra.

UnnERnEjai/fiNe-BIT.

application med Mayer, 191e. serieu no. 190,945.-

To all whom t may concern:

Be it known that l, HENRY J. Fnnnoit, a citizen of the United States, residing at Santa Maria, in the county of Santa Bar bara and State of'Caliornia, have invented new and useful Improvements in Under'- reaniing-Bits, of which the following is a specification.

My invention relates to a well drilling bit.

It is an object of this invention to construct a well drilling' bit consisting oi a main body portion anda cutting portion pivoted to the main body portion. Means are provided for causing the cutting portion to project outwardly from the 'vertical cylinder in which the bit is reciprocated in digging the well, whereby the bore of the well immediately below the lowermost casing in the well iscut away underneath said casing thereby permitting the latter to bemoved downwardly in the bore which is of sufficient cross sectional area to allow the downward movement of the casing without offering any obstruction. v

It is another object of this invention to provide a bit which'in its loperation forms a snug lit in the casing, thereby providing a large yguiding surface but which allows the edge of the cutting portion Lto cut away or underream the bore immediately beneath the walls of the casing. The width 01:' this eXtra cut will depend upon the size of the wal-ls of the easing employed and will usually not exceed one-half of an inch, but may be of any size desired. l

It is another object of this invention to construct a bit which is simple, ldurable and not liable to get out of order.

With the above and other objects in View which will appear as the description proceeds, my invention consists in the construction, combination and arrangement of parts hereinafter described and claimed.

In the accompanying Adrawings which form a part of this specification, I have illustrated a conve-nient and practical embodiment ol. my invention in which:

Figure 1 is a side elevation of my improved underreaming bit showing 4its opera-` tion in the bottom of a well.

Fig. 2 is a side elevation of the bit removed from the casing and taken at right angles from the bit shown in Fig. l.

Fig. 3 is a horizontal section on line 3 3 of Fig. 2. v My improved bit comprises an upper body Specification of Letters Patent.

Patentedllaiin er, rear;

portion 10 provided with al connecting neck 11 at its upper end, whereby the same is attached to the drilling gear operatingA the bit. The bit has substantiallytlie shape o f a cylinder 'of a size to ht snugly inthe wellccas-i ing 12. fr pair of vertical water Vchannels 13 disposed on opposite. sides `ol" the body portion 1() are provided which Vallow the water or "oil in the'well to pass freely from beI low the bit to the kspace abovethe same. At the lower end ofthe `main boi'dy portion l0, anden opposite sides thereof, `a pair of de pending' semi-circular bearing lugs 14, 14 are provided between which a semi-circular recess 515 `is "ilo'rined` rThe recess l5`serves for the reception of `a bea-ring lug 16 `of corresponding shape which extends centrally upward from the end of the pivoted cutting portion 17. The upper end ofthe cutting portion 17y is Acut away on vopposite `sides to form a pair ot semi-circular bearingrecesses 18,18 for the Ireception' of vthe depending lugs 14, 141 of vthe upper body portion. A pin 19 passes horizontally through suitable apertures of the dependinglugs 14 and the central lug 16, iorining ya pivot on which the cutting portionA 17 may be oscillated or rocked. In order to lessen the strain onthe As clearly shown in Fig. 1,l the top face; of the `cutting portion 17 on 'opposite-sides of the pivot pin 19 are slightly inclined from the horizontal permitting't-he cutting por-4 tion 17 to be oscillated on its pivot to a slight degree, so Athat the cutting edge u21 thereof will projectoutwardly beyond the vertical and enable said edge to 'underream or undercut the space immediately beneath the walls of the casing 12. 30 30 designate a pair of vertical water channels oppositely arranged on the cuttingportion 17 In `order to cause a positive movement of the -cutting edge 21 outwardly away from the interior cylinder of the casing 12, I have provided 'the following mechanism The body portion 10 is provided with "a vertical bore 22 near the vertical face thereof, and

vextending throughout the length of said body portion. A rod 23 is disposed therein, whose lower extremity is pivoted to the cutting portion 17 by a pin 24;. A helical compression spring 25 surrounds the rod 23. The lower end of the spring rests against a shoulder 26 formed in the lower end of the bore 22 and its movable upper end abuts against a nut 27 on the upper threaded end of the rod 23. The spring 25 tends to move the end of the cutting portion 17 which is attached to the rod 28 in Lclose contact with the adjacent part of the body portion 10 so that as soon as the cutting portion 17 projects below the lower extremity of the cas- Y ing 12, the cutting edge 21 of the cutting Y tated. The cutting edge, as soon as the bit portion 17 will project outwardly as clearly shown in Fig. 1, and thus underream the Vwalls' of the casing l2.

Fromthe foregoing description, the operation of my improved underreaming well drilling bit will be easilyunderstood. In the operation, the bit is reciprocated and ro- Y works below the lower extremity of the well casing, will project outwardly from the walls thereof by the action of the spring 25, the tension of which may be adjusted by ad- Y justing the nut 27, and underream said casing. It should be noted that the relatively 'l v large body portionwhich tssnugly in the well casing will act as a guide, causing the cutting edge to cut and underream the well casing the desired amount. In withdrawing the-bit, the cutting edge will, as it passes struction, arrangement and combination of parts may be made without departing from my invention and the scope of the appended claims.

I claim:

1. In a well drilling bit, the combination l 'l of acylindricalbody portion of a size to fit Y Copies of this patent may be obtained for snugly the wellcasing in which it operates, a cylindrical cutting portion in axial alinement with said body portion and forming an extension thereof, saidv cutting portion being pivoted at its upper end to the lower end of said body portion and adapted to rock in ak vertical plane, means `for limiting the rock movementL of said cutting portion and a spring mounted in said body portion and opera-tively connected with said cutting portion for moving the latter out of alinement with said body portion, whereby said cutting portion will underream the casing.

2. In a well drilling bit, the combination of a body portion of a size to iit snugly the well casing in which it operates, a cutting portion in axial alinement with said body portion and forming an extension thereof, said cutting portion being pivoted at its upper end to the lower end of said body portion and adapted to rock in a vertical plane, a shoulder on said body portion for limiting the outward movement of said cutting portion, a shoulder on said cutting portion adapted to engage said iirst named shoulder, and a tension spring mounted in said body portion and acting on said cutting portion to cause the shoulder thereof to Vmove toward the shoulder on said body portion.

3. In a well drilling bit, the combination of a body portion of a size to lit snugly the well casing in which it operates, a cutting portion in axial alinement with said body portion and forming an extension thereof, means for pivoting said cutting portion to said body portion to permit the former to swing in a vertical plane, means on said body portion to limit the swinging move` ment of said cutting portion, and resilient means tending to swing said cutting portion toward said limiting means.

Ll. In a well drilling bit, the combination of a body portion of a size to it snugly the well casing in which it operates, a cutting portion in axial alinementwith said body portion and forming an extension thereof, means for pivoting the upper end of said cutting portion to the lower end of said body portion to permit the latter to swing in a vertical plane, a pair of shoulders on opposite sides of the lower end of said body portion for limiting the swinging movement of said cutting portion, a pair of shoulders on the upper end of said cutting portion, adapted to coperate with said shoulders of said body portion, said body portion being provided with a spring chamber, a spring rod located therein and pivotally connected to a shoulder of said cutting portion, and a tension spring acting on said rod and tending to move the shoulder of said cutting portion connected to said rod in engagement with the shoulder of said body portion adjacent thereto.

In testimony whereof I have signed my name to this specification.

HENRY J. FREEON.

ve cents each, by addressing the Commissioner of Patents.l Washington, D. C. 

